September 13, 2013 Objective: To describe homeostasis and use medical terminology effectively Journal: What is homeostasis?
Homeostasis
Video http://education- portal.com/academy/lesson/homeostasis- and-temperature-regulation-in-humans.html
Homeostasis Physiological mechanisms that work to maintain a constant internal environment Examples?
Components of Homeostatic Mechanisms Receptor – detects stimuli and sends signal on an afferent pathway to the control center. Control Center – interprets signal and decides how to act. Effector – information flows from the control center along the efferent pathway to the effector.
How do homeostatic mechanisms work? If the body detects that its normal set-point is either to high or to low it will respond. Control Center Efferent Pathway Afferent Pathway Receptor (Start) Effector
Example When your body gets to hot, what happens? Send signal to control center in the brain Brain signals a response Sweat is released and blood vessels get bigger
Positive Feedback Loops Loop continues in the same direction and increases magnitude of change to the body
Negative Feedback Loops Loop moves in the opposite direction of a stimulus
Determine if the scenario represents a positive or negative feedback homeostatic system: A car starts rolling out of a driveway w/o a driver. A person decides to respond by pushing the car in the direction that makes it leave the driveway faster. Your blood calcium level is low so your body begins to break down bone tissue so that calcium is released into the blood. A neuron is stimulated and sodium goes rushing into the cell. The more it is stimulated the more sodium goes rushing in, thus enhancing the stimulus.
Metabolism In order to maintain homeostasis many chemical reactions have to take place in your body. These chemical reactions are collectively called your metabolism
Two Types of Metabolic Pathways: 1. Anabolism – the process by which simpler compounds are built up and used for growth, repair and reproduction. Examples - cellular respiration to ATP 2. Catabolism – the process by which complex substances are broken down into simpler substances. Examples – hydrolysis of fats or glycogen.